Page 127 - The Toyota Way Fieldbook

104 THE TOYOTA WAY FIELDBOOK

Case Example: Connecting Operations to Surface Waste
in Engineering

An automotive seat supplier had a very elaborate “phase-gate process”
for developing new products. Each phase in the process of developing
a vehicle had been defined in detail. The criteria for predefined “gates”
for the product design was clear, and if upon review the design did not
meet all those criteria, it would not pass to the next step in the process.
This process was taught to everyone so they knew what to do in the
process and when to do it.

One of our associates worked with them as a consultant to develop a
value stream map of the current process and discovered that it did
not match the phase-gate process on paper very well (a common
finding). There were constant delays causing backups in the system
and no good flow. A future state vision was developed, and they
went to work stabilizing subprocesses and then, somewhat crudely,
connecting them together.
One of the bottlenecks in the current state was the process of producing
and testing prototypes. Seats were designed, parts were ordered, and
hundreds of prototypes built and tested.
When that process was mapped, it became clear that this was a classic
case of batch and scheduled push (see Figure 5-10). All the seats were
completely designed, including heated, not heated, bench, captain’s
chairs, power, and so on. Based on the designs, parts were ordered.
The parts arrived at various times from suppliers. The prototype group
waited as long as they could for all the parts they needed and then
started building whatever seats they could with the parts they had.
Then they released lots of seats to testing. Seats that failed testing
had to be redesigned to correct the problems.
A future state map was developed. It became clear that the fundamental
problem was batching. Each step in the process developed large batches
and pushed to the next process. The inventory triangles in the current
state diagram show the result—inventory. In the case of seat designs,
it was an inventory of information—the designs—accumulating in front
of parts ordering. The solution: Create a sequenced pull system. But

Design Order Build
Seats I Parts I Prototypes I Test

Figure 5-10. Current state map of prototyping process